The valency concept provides a model capable of dealing with the semantic and syntactic aspects of the relationship between typically verbal predicates and their typically nominal actants in sentences. By contrast, the corresponding relations obtaining within complex predicates have remained largely unexplored. What - from a valency point of view - are the relations, in complex predicates such as faire faillite, between the formally verbal formative faire and the formally non-verbal predicate nucleus faillite? This is the central issue that the present study sets out to resolve in connection with French mulit-word verb structures such as êtres en mouvement.